Controllable Electrical Outlet Having a Resonant Loop Antenna

ABSTRACT

A controllable electrical outlet may comprise a resonant loop antenna. The resonant loop antenna may comprise a feed loop electrically coupled to a radio-frequency (RF) communication circuit and a main loop magnetically coupled to the feed loop. The controllable electrical outlet may comprise one or more electrical receptacles configured to receive a plug of a plug-in electrical load and may be configured to control power delivered to the plug-in electrical load in response to an RF signal received via the RF communication circuit. The RF performance of the controllable electrical outlet may be substantially immune to devices plugged into the receptacles (e.g., plugs, power supplies, etc.) due to the operation of the resonant loop antenna. For example, degradation of the RF performance of the controllable electrical outlet may be less when the controllable electrical outlet includes the resonant loop antenna rather than other types of antennas.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. Non-Provisional patentapplication Ser. No. 16/713,097 filed on Dec. 13, 2019; which is acontinuation of U.S. Non-Provisional patent application Ser. No.15/496,659, filed on Apr. 25, 2017, now U.S. Pat. No. 10,535,996, issuedJan. 13, 2020; which claims the benefit of U.S. Provisional PatentApplication No. 62/327,163, filed Apr. 25, 2016, the entire disclosuresof which are incorporated by reference herein.

BACKGROUND

Many consumers reduce the total cost of electrical energy by reducingthe total energy usages of electrical loads, such as lighting loads. Forexample, lighting loads are often controlled in response to occupancyand vacancy sensors, which detect occupancy and/or vacancy conditions ina space, to save energy. Typically, the lighting loads are turned onwhen the space is occupied and turned off when the space is unoccupied.In addition, consumers are becoming more sensitive to the amount ofenergy consumed by electrical loads, such as plug-in electrical loadsthat are plugged into electrical receptacles. Such plug-in electricalloads may still consume energy to maintain a standby mode when “turnedoff” and are often referred to as “vampire” loads.

Some standards (such as ASHRAE 90.1 and California Title 24) are nowrequiring that many electrical outlets installed in new construction ormajor renovations must be controlled (e.g., switched) to provide energysavings. For example, the electrical outlets may be controlled inresponse to a timeclock and/or an occupancy or vacancy sensor. Suchelectrical outlets may be coupled to a communication link (e.g., a wiredor wireless digital communication link) and may be configured to receivedigital messages including commands for controlling the plug-inelectrical loads (e.g., in response to the timeclock and/or theoccupancy or vacancy sensor).

SUMMARY

As described herein, a controllable electrical outlet for use in a loadcontrol system adapted to receive power from a power source may comprisea resonant loop antenna for receiving a radio-frequency (RF) signal. Theresonant loop antenna may comprise a feed loop electrically coupled toan RF communication circuit and a main loop magnetically coupled to thefeed loop. The controllable electrical outlet may comprise one or moreelectrical receptacles configured to receive a plug of a plug-inelectrical load and an electrical connection configured to beelectrically coupled to the power source to receive a hot voltage. Thecontrollable electrical outlet may also comprise a load control circuitelectrically coupled in series between the electrical connection and theelectrical receptacle to control power delivered to the plug-inelectrical load, and a control circuit coupled to the load controlcircuit and the communication circuit to control power delivered to theplug-in electrical load in response to an RF signal received via the RFcommunication circuit. The RF performance of the controllable electricaloutlet may be substantially immune to devices plugged into thereceptacles (e.g., plugs, power supplies, control devices, etc.) due tothe operation of the resonant loop antenna. For example, degradation ofthe RF performance of the controllable electrical outlet may be lesswhen the controllable electrical outlet includes the resonant loopantenna rather than other types of antennas, such as a monopole antenna.

In addition, the controllable electrical outlet may comprise a mainprinted circuit board on which the load control circuit is mounted. Theresonant loop antenna may comprise an antenna printed circuit boardcomprising first and second layers and arranged perpendicular to themain printed circuit board. The first layer may have a main loop tracecharacterized by an inductance and a capacitance that are resonant atthe specified frequency. The second layer may have a feed loop traceelectrically coupled to the RF communication circuit and magneticallycoupled to the main loop trace.

Further, an electrical contact of one of the receptacles may be coupledto an electrical contact of the other receptacle by an electricalcontact coupling member. The main loop trace of the antenna printedcircuit board may be mostly located above the coupling member in adirection extending from the main printed circuit boards towards a frontsurface of the electrical outlet. A top edge of a lower portion of themain loop trace of the antenna printed circuit board may be positionedabove the coupling member in a direction extending from the main printedcircuit boards towards a front surface of the electrical outlet. Aninner portion of the main loop trace of the antenna printed circuitboard may not overlap with the coupling member when viewed from theside.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a simple diagram of an example load control system having acontrollable electrical outlet.

FIG. 2 is a simplified block diagram of an example controllableelectrical outlet.

FIG. 3 is a perspective view of an example controllable electricaloutlet.

FIG. 4 is a front view of another example controllable electricaloutlet.

FIG. 5 is a front view of a portion of the controllable electricaloutlet of FIGS. 3 and 4.

FIG. 6 is a left side view of the portion of the controllable electricaloutlet shown in FIG. 5.

FIGS. 7 and 8 show first and second layers of an antenna printed circuitboard.

FIG. 9 shows an example equivalent circuit of a resonant loop antenna.

DETAILED DESCRIPTION

FIG. 1 is a simple diagram of an example load control system 100 havinga load control device (e.g., a controllable electrical outlet 110), aplurality of standard electrical outlets 120, and a plurality of plug-inelectrical loads (e.g., a computer 104 and a monitor 106). Thecontrollable electrical outlet 110 may be adapted to be installed in astandard electrical wallbox (not shown). The controllable electricaloutlet 110 may be adapted to be connected to a power source, such as analternating-current (AC) power source 102 for receiving a hot voltageV_(H) (e.g., an AC mains line voltage, such as 120 V at 60 Hz or 230 Vat 50 Hz) at a line voltage input 115 (e.g., a hot terminal). Thecontrollable electrical outlet 110 may also be connected to the neutralside of the AC power source 102. Alternatively or additionally, thecontrollable electrical outlet 110 may be configured to receive powerfrom a direct-current (DC) power source.

The controllable electrical outlet 110 may comprise upper and lowerreceptacles 112, 114 into which the plug of a plug-in electrical loadmay be plugged. Each receptacle 112, 114 may have a hot connection and aneutral connection for receipt of the corresponding prongs of anelectrical plug. The controllable electrical outlet 110 may provide thehot voltage V_(H) at the upper receptacle 112, such that any electricalloads plugged into the upper receptacle are continuously powered. Thecontrollable electrical outlet 110 may comprise an internal load controlcircuit (not shown), e.g., a relay for generating a switched-hot voltageV_(SH), which may be provided at the lower receptacle 114. Accordingly,any electrical loads plugged into the lower receptacle 114 may bepowered and unpowered in response to closing and opening the relay,respectively. Alternatively, the upper and lower receptacles 112, 114could both provide the hot voltage V_(H) or both could provide theswitched-hot voltage V_(SH), or the controllable electrical outlet 110may provide the hot voltage V_(H) at the lower receptacle 114 and theswitched-hot voltage V_(SH) at the upper receptacle 112.

The controllable electrical outlet 110 may also comprise a controlledwired output 116 (e.g., a switched-hot terminal) for providing theswitched voltage V_(SH) to the standard electrical outlets 120. Thestandard electrical outlets 120 may each be configured to receive boththe hot voltage V_(H) and the switched-hot voltage V_(SH). For example,the standard electrical outlets 120 may receive the hot voltage V_(H)via an electrical wire 126 connected to the line voltage input 115 ofthe controllable electrical outlet 110. The standard electrical outlets120 may receive the switched-hot voltage V_(SH) via an electrical wire128 connected to the controlled wired output 116 of the controllableelectrical outlet 110. One or more of the standard electrical outlets120 may also be connected to the neutral side of the AC power source102. The controllable electrical outlet 110 may “pass through” the hotvoltage V_(H) to provide the hot voltage V_(H) from the AC power source102 to the electrical wire 126 (e.g., directly). Alternatively, theelectrical wire 126 may be wired to the hot side of the AC power source102 around the controllable electrical outlet 110, such that the hotvoltage V_(H) does not pass through the controllable electrical outlet110 on its way to the standard electrical outlet 120.

Each of the standard electrical outlets 120 may comprise upper and lowerreceptacles 122, 124 into which an electrical load may be plugged. Theupper receptacle 122 of a standard electrical outlet 120 may beelectrically coupled to the electrical wire 126 for receiving the hotvoltage V_(H), such that any electrical loads plugged into the upperreceptacles are continuously powered. The lower receptacle 124 of astandard electrical outlet 120 may be electrically coupled to theelectrical wire 128 for receiving the switched-hot voltage V_(SH), suchthat any electrical loads plugged into the lower receptacle may bepowered and unpowered in response to the closing and opening,respectively, of the relay of the controllable electrical outlet 110.Referring to the example of FIG. 1, the computer 104 may be adapted tobe plugged into the upper receptacle 122 of one of the standardelectrical outlets 120 (e.g., such that the computer 104 may becontinuously powered), while the monitor 106 may be adapted to beplugged into the lower receptacle 124 of one of the standard electricaloutlets (e.g., such that the monitor 106 may be turned on and off by thecontrollable electrical outlet 110. Alternatively, the upper and lowerreceptacles 122, 124 of a standard electrical outlet 120 could both becoupled to the hot voltage V_(H) or could both be coupled to theswitched-hot voltage V_(SH).

The controllable electrical outlet 110 may be configured to measure themagnitude of the total load current conducted by one or more of theplug-in electrical loads plugged into the controllable electrical outlet110 and/or the standard electrical outlets 120. For example, thecontrollable electrical outlet 110 may be configured to measure themagnitude of a first load current conducted by the switched electricalloads (e.g., the electrical loads connected to the lower receptacle124), and the magnitude of a second load current conducted by theunswitched electrical loads (e.g., the electrical loads connected to theupper receptacle 122).

The controllable electrical outlet 110 may be configured to control therelay to turn the electrical loads plugged into the lower receptacles114, 124 and/or the standard electrical outlets 120 on and off inresponse to wireless signals, e.g., radio-frequency (RF) signals 108,received from one or more input devices (e.g., RF transmitters). Forexample, the input devices may comprise a remote control device 130, anoccupancy sensor 140, and/or a system controller 150 (e.g., a centralcontroller or gateway device). As such, the controllable electricaloutlet 110 may be controlled automatically (e.g., via an occupancysensor 140) or manually (e.g., via a remote control device 130). Becausethe controllable electrical outlet 110 has the controlled wired output116 for controlling the standard electrical outlets 120, the standardelectrical outlets do not need to be responsive to the RF signals 106 inorder to switch the respective plug-in electrical loads on and off, thusgreatly reducing the cost of the load control system 100.

The remote control device 130 may comprise a battery-powered handheldremote control, or could alternatively be mounted to a wall or supportedon a pedestal to be mounted on a tabletop. Examples of battery-poweredremote control devices are described in greater detail incommonly-assigned U.S. Pat. No. 8,330,638, issued Dec. 11, 2012,entitled WIRELESS BATTERY-POWERED REMOTE CONTROL HAVING MULTIPLEMOUNTING MEANS, the entire disclosures of which are hereby incorporatedby reference.

The remote control device 130 may transmit digital messages to thecontrollable electrical outlet 110 via the RF signals 108 in response toactuations of one or more buttons 132 for turning the electrical loadsplugged into the lower receptacles 114, 124 on and off. The remotecontrol device 130 may be associated with the controllable electricaloutlet 110 by actuating one or more of the buttons 132 of the remotecontrol device and an actuator (e.g., programming button 118) of thecontrollable electrical outlet 110. The controllable electrical outlet110 may also comprise a visual indicator 119, e.g., a light-emittingdiode (LED), which may be illuminated to provide feedback to a userduring configuration and/or normal operation. Since the controllableelectrical outlet 110 may be adapted to be installed in a standardelectrical wallbox and the programming button 118 may be located on thecontrollable electrical outlet 110, the programming button 118 may beeasily accessed to associate the controllable electrical outlet 110 withthe remote control device 130. In addition, the controllable electricaloutlet 110 may be installed in the same room in which the remote controldevice 130 is located to enhance the reliability of the RFcommunications. Examples of methods of associating wireless controldevices are described in greater detail in commonly-assigned U.S. PatentApplication Publication No. 2008/0111491, published May 15, 2008,entitled RADIO-FREQUENCY LIGHTING CONTROL SYSTEM; U.S. Pat. No.9,368,025, issued Jun. 14, 2016, entitled TWO-PART LOAD CONTROL SYSTEMMOUNTABLE TO A SINGLE ELECTRICAL WALLBOX; and U.S. Patent ApplicationPublication No. 2014/0265568, published Sep. 18, 2014, entitledCOMMISSIONING LOAD CONTROL SYSTEMS; the entire disclosures of which arehereby incorporated by reference.

The occupancy sensor 140 may be configured to detect occupancy andvacancy conditions in the space in which the load control system 100 isinstalled. The occupancy sensor 140 may transmit digital messages to thecontrollable electrical outlet 110 via the RF signals 108 in response todetecting the occupancy or vacancy conditions. The controllableelectrical outlet 110 may be configured to turn the electrical loadsplugged into the lower receptacles 114, 124 on in response to anoccupancy condition and off in response to a vacancy condition. Theoccupancy sensor 140 may be associated with the controllable electricaloutlet 110 by actuating a button on the occupancy sensor and/or anactuator (e.g., the programming button 118) of the controllableelectrical outlet 110. Since the controllable electrical outlet 110 maybe located in the same room as the occupancy sensor 140, the occupancysensor 140 may be easily associated with the controllable electricaloutlet 110 and reliable RF communications may be provided.Alternatively, the occupancy sensor 140 may operate as a vacancy sensorto only turn off the lighting loads in response to detecting a vacancycondition (e.g., to not turn on the lighting loads in response todetecting an occupancy condition). Examples of RF load control systemshaving occupancy and vacancy sensors are described in greater detail incommonly-assigned U.S. Pat. No. 8,009,042, issued Aug. 30, 2011 Sep. 3,2008, entitled RADIO-FREQUENCY LIGHTING CONTROL SYSTEM WITH OCCUPANCYSENSING; U.S. Pat. No. 8,199,010, issued Jun. 12, 2012, entitled METHODAND APPARATUS FOR CONFIGURING A WIRELESS SENSOR; and U.S. Pat. No.8,228,184, issued Jul. 24, 2012, entitled BATTERY-POWERED OCCUPANCYSENSOR, the entire disclosures of which are hereby incorporated byreference.

The system controller 150 may be configured to communicate with anetwork 152 (e.g., a wireless or wired local area network) via a wireddigital communication link 154 (e.g., an Ethernet communication link)for access to the Internet. Alternatively or additionally, the systemcontroller 150 may be wirelessly connected to the network 152, e.g.,using LTE or Wi-Fi technology. For example, the system controller 150may be configured to receive digital messages (e.g., Internet Protocolpackets) via the network 152 from a network device (not shown), such asa smart phone (e.g., an iPhone® smart phone, an Android® smart phone, ora Blackberry® smart phone), a personal computer, a laptop, awireless-capable media device (e.g., MP3 player, gaming device, ortelevision), a tablet device, (e.g., an iPad® hand-held computingdevice), a Wi-Fi or wireless-communication-capable television, or anyother suitable Internet-Protocol-enabled device. Examples of loadcontrol systems operable to communicate with network devices on anetwork are described in greater detail in commonly-assigned U.S. PatentApplication Publication No. 2013/0030589, published Jan. 31, 2013,entitled LOAD CONTROL DEVICE HAVING INTERNET CONNECTIVITY, the entiredisclosure of which is hereby incorporated by reference.

The system controller 150 may operate as a central controller for theload control system 100. The system controller 150 may operate as agateway device to simply relay digital messages between the network 152and the controllable electrical outlet 110. The system controller 150may be configured to transmit digital messages via the RF signals 108 tothe controllable electrical outlet 110 for turning on and off theelectrical loads plugged into the controllable electrical outlet 110and/or the standard electrical outlets 120. Accordingly, thecontrollable electrical outlet 110 may be responsive to data received bythe system controller 150 from the Internet, such as weather informationand emergency status information. The system controller 150 may befurther configured to transmit digital messages including one or moreof: a timeclock command, a load shed command, a demand response command,a peak demand command, or time-of-day pricing information. The systemcontroller 150 may be configured to control the controllable electricaloutlet 110 in accordance with one or more timeclock events of atimeclock schedule, for example, to turn on the switched electricalloads during the day and to turn off the switched electrical loads atnight. In addition, the controllable electrical outlet 110 may beconfigured to transmit feedback information, such as the status andenergy consumption of the controlled loads (e.g., load current), back tothe system controller 150, which may be configured to report theinformation to an external device via the network 152.

The controllable electrical outlet 110 may be configured to storeinformation regarding the type of input device from which thecontrollable electrical outlet 100 received the digital message. Thecontrollable electrical outlet 110 may be configured to storeinformation regarding how the controllable electrical outlet 110controlled the electrical loads in response to receiving the digitalmessage. For example, this may be performed by the controller electricaloutlet 110 after controlling the electrical loads plugged into thecontrollable electrical outlet 110 and/or the standard electricaloutlets 120 in response to digital messages received via the RF signals108. The controllable electrical outlet 110 may transmit thisinformation to the system controller 150. The system controller 150 mayanalyze this information to determine how much energy is saved inresponse to certain types of input devices. For example, the systemcontroller 150 may be configured to determine how much energy is savedas a result of the controllable electrical outlet 110 turning off theelectrical loads plugged into the controllable electrical outlet 110and/or the standard electrical outlets 120 in response to the occupancysensor 140 versus how much energy is saved as a result of thecontrollable electrical outlet turning off the electrical loads inresponse to the remote control device 130.

The controllable electrical outlet 110 may be configured to determine abalance between the amount of power consumed by the switched andunswitched electrical loads and report this information to the systemcontroller 150. The system controller 150 may be configured to transmit(e.g., to a network device via the network 152) a digital messageincluding an alert that the amount of power consumed by the switched andunswitched electrical loads is unbalanced, for example, if theunswitched electrical loads are consuming a much greater amount of powerthan the switched electrical loads. For example, the alert may beincluded in an email or text message sent to a building manager.

Some plug-in electrical loads may still consume energy to maintain astandby mode when off. These electrical loads may be referred to as“vampire” loads. In addition, some plug-in power supplies may stillconsume energy even when the power supply is not charging a rechargeableload. The controllable electrical outlet 110 may be configured to detectwhether one or more of the plug-in electrical loads plugged into thecontrollable electrical outlet 110 and/or the standard electricaloutlets 120 are off, are in the standby mode, and/or are not charging arechargeable load. The controllable electrical outlet 110 may beconfigured to determine that a plug-in electrical load is off, is instandby mode, and/or is not charging a rechargeable load if themagnitude of the load current conducted by the plug-in electrical loadis less than a predetermined current threshold. For example, thecontrollable electrical outlet 110 may be configured to remove powerfrom the plug-in electrical load if the controllable electrical outlethas received a digital message indicating a vacancy condition from theoccupancy sensor 140 and has determined that the plug-in electrical loadis off, is in the standby mode, and/or is not charging a rechargeableload. The controllable electrical outlet 110 will not remove power fromthe plug-in electrical load when the load is on or charging. Forexample, if a television is on, the television is considered to be inuse independent of whether the room is occupied or not. Perhaps the useris listening to a particular program on the television from anotherroom. When the television is turned off (e.g., changed to standby mode),the controllable electrical outlet 110 may disconnect the televisionfrom the AC power source when the room becomes unoccupied, for example,to save energy.

Some plug-in electrical loads may be critical loads that should becontinuously powered (e.g., computers, medical devices, etc.). Thecontrollable electrical outlet 110 may be configured to determine if acritical load is plugged into the controllable electrical outlet 110and/or the standard electrical outlets 120 and to prevent the criticalload from being turned off, e.g., by disabling control of the criticalload by the input devices (e.g., the remote control device 130, theoccupancy sensor 140, and/or the controller 150). For example, thecontrollable electrical outlet 110 may be configured to determine thatthe computer 104 is plugged into one of the controllable electricaloutlet 110 and/or the standard electrical outlets 120 by monitoring anelectrical signature of the load current drawn by the computer. Thecontrollable electrical outlet 110 may be configured to record and storethe electrical signature of the load current conducted by the computer104 when the computer 104 is plugged into the controllable electricaloutlet 110 and/or the standard electrical outlets 120, e.g., when theload control system 100 is first configured after installation. Thecontrollable electrical outlet 110 may also have one or morepredetermined electrical signatures of critical loads stored in memoryprior to installation. During normal operation, the controllableelectrical outlet 110 may be configured to compare an electricalsignature drawn by an electrical load to one or more of the plurality ofelectrical signatures stored in memory. If the controllable electricaloutlet 110 determines that an electrical load plugged into thecontrollable electrical outlet 110 and/or a standard electrical outlet120 is a critical load via its electrical signature (e.g., that theelectrical load is the computer 104), the controllable electrical outlet110 may be configured to continuously power the electrical load at alltimes, e.g., by not disconnecting power from the electrical load inresponse to the remote control device 130, the occupancy sensor 140,and/or the controller 150.

The controllable electrical outlet 110 may be configured to determinethat the room in which an electrical load (e.g., the computer 104 and/orthe monitor 106) is located is occupied in response to the magnitudes ofthe load currents conducted by the switched and/or unswitched electricalloads. For example, if the magnitude of the load current conducted bythe computer 104 has increased and/or is actively changing, thecontrollable electrical outlet 110 may be configured to determine thatthe room in occupied. If the controllable electrical outlet 110determines that one or more of the electrical loads plugged into thecontrollable electrical outlet 110 and/or the standard electricaloutlets 120 are off, are in the standby mode, and/or are not charging arechargeable load, the controllable electrical outlet 110 may determinethat the room is vacant. The controllable electrical outlet 110 may beconfigured to turn on and off the electrical loads plugged into thecontrollable electrical outlet 110 and/or the standard electricaloutlets 120 in response to the occupancy and/or vacancy conditionsdetermined from the magnitudes of the load currents.

As described above, the remote control device 130, the occupancy sensor140, and/or the system controller 150 may operate as a control-sourcedevice (e.g., an RF transmitter) and the controllable electrical outlet110 may operate as a control-target device (e.g., an RF receiver).Alternatively or additionally, the control devices of the load controlsystem 100 may comprise an RF transceiver, such that the devices areable to transmit and receive the RF signals 108. For example, thecontrollable electrical outlet 110 may be configured to transmitfeedback information, such as the status and energy consumption of thecontrolled loads, back to the system controller 150, which may beconfigured to report the information to external devices via the network152. Examples of RF load control systems are described incommonly-assigned U.S. Pat. No. 5,905,442, issued on May 18, 1999,entitled METHOD AND APPARATUS FOR CONTROLLING AND DETERMINING THE STATUSOF ELECTRICAL DEVICES FROM REMOTE LOCATIONS, and U.S. Pat. No.9,553,451, issued Jan. 24, 2017, entitled LOAD CONTROL SYSTEM HAVINGINDEPENDENTLY-CONTROLLED UNITS RESPONSIVE TO A BROADCAST CONTROLLER, theentire disclosures of which are both hereby incorporated by reference.

In addition, the controllable electrical outlet 110 may operate a signalrepeater of the load control system 100. For example, the controllableelectrical outlet 110 may be configured to receive a digital messagefrom one of the control devices of the load control system 100 (e.g.,the remote control device 130, the occupancy sensor 140, the systemcontroller 150, or another controllable electrical outlet) and toretransmit the digital message to other control devices of the loadcontrol system (e.g., the system controller 150 or another controllableelectrical outlet). Examples of RF load control systems having signalrepeaters are described in greater detail in commonly-assigned U.S. Pat.No. 5,848,054, issued Dec. 8, 1998, entitled REPEATER FOR TRANSMISSIONSYSTEM FOR CONTROLLING AND DETERMINING THE STATUS OF ELECTRICAL DEVICESFROM REMOTE LOCATIONS, and U.S. Pat. No. 6,803,728, issued Oct. 12,2004, entitled SYSTEM FOR CONTROL OF DEVICES, the entire disclosures ofwhich are hereby incorporated by reference.

Since the controllable electrical outlet 110 may be adapted to beinstalled in the standard electrical wallbox and may be responsive tothe RF signals 108 (e.g., that are transmitted directly to thecontrollable electrical outlet 110), the load control system 100 may notrequire any additional control devices (e.g., load control devicesinstalled above the ceiling of the room, behind the walls of the room,or in an electrical closet) in order to provide control of theelectrical loads plugged into the controllable electrical outlet 110 andthe standard electrical outlets 120 in response to the RF signals 108.This reduces the overall cost of the load control system 100 andsimplifies the installation of the load control system 100 since noadditional control devices need to be installed.

The controllable electrical outlet 110 could be responsive to othertypes of input devices, such as, for example, daylight sensors,radiometers, cloudy-day sensors, shadow sensors, window sensors,temperature sensors, humidity sensors, pressure sensors, smokedetectors, carbon monoxide detectors, air-quality sensors, motionsensors, security sensors, proximity sensors, fixture sensors, partitionsensors, keypads, kinetic or solar-powered remote controls, key fobs,cell phones, smart phones, tablets, personal digital assistants,personal computers, laptops, timeclocks, audio-visual controls, safetydevices (such as fire protection, water protection, and medicalemergency devices), power monitoring devices (such as power meters,energy meters, utility submeters, utility rate meters), residential,commercial, or industrial controllers, interface devices with othercontrol systems (such as security systems and emergency alert systems),and/or any combination of these input devices. One or more of thedifferent types of input devices may be provided in a single loadcontrol system 100.

The load control system 100 may also comprise one or more other types ofplug-in electrical load and/or switched electrical loads, such as, forexample, lighting loads (e.g., incandescent lamps, halogen lamps,electronic low-voltage lighting loads, and magnetic low-voltage lightingloads); dimming ballasts for driving gas-discharge lamps; light-emittingdiode (LED) drivers for driving LED light sources; table or floor lamps;screw-in luminaires including dimmer circuits and incandescent orhalogen lamps; screw-in luminaires including ballasts and compactfluorescent lamps; screw-in luminaires including LED drivers and LEDlight sources; motor loads, such as ceiling fans and exhaust fans;motorized window treatments; projection screens; motorized interior orexterior shutters; heating and/or cooling systems; heating, ventilation,and air-conditioning (HVAC) systems; air conditioners; compressors;electric baseboard heater controllers; controllable dampers; variableair volume controllers; fresh air intake controllers; ventilationcontrollers; hydraulic valves for use in radiators and radiant heatingsystem; humidity control units; humidifiers; dehumidifiers; waterheaters; boiler controllers; pool pumps; refrigerators; freezers;appliances; televisions; computer monitors; printers; copiers; faxmachines; video cameras; audio systems; amplifiers; speakers; overheadprojectors; visual presenters; smart boards; coffee makers; toasters;elevators; power supplies; generators; electric chargers; electricvehicle chargers; medical devices (e.g., heart/lung machines), oralternative energy controllers.

FIG. 2 is a simplified block diagram of an example controllableelectrical outlet 200 that may be deployed as, for example, thecontrollable electrical outlet 110 of the load control system 100 shownin FIG. 1. The controllable electrical outlet 200 may be adapted to bemounted in a standard electrical wallbox. As shown, the controllableelectrical outlet 200 may include a line-side hot electrical connectionH_(LINE) (e.g., the line voltage input 115) and a line-side neutralelectrical connection N_(LINE). The line-side hot electrical connectionH_(LINE) and the line-side neutral electrical connection N_(LINE) may becoupled to an AC power source 202 (e.g., the AC power source 102) forreceiving a power source voltage (e.g., the hot voltage V_(H)) from theAC power source 202. The controllable electrical outlet 200 may furthercomprise a first load-side hot electrical connection H_(LOAD1) and afirst load-side neutral electrical connection N_(OUT1), which may beprovided at an electrical receptacle (e.g., the upper unswitchedreceptacle 112 of the controllable electrical outlet 110) for powering afirst electrical load (e.g., a first plug-in electrical load). The hotvoltage V_(H) received at the line-side hot electrical connectionH_(LINE) may be fed through the controllable electrical outlet 200 tothe first load-side hot electrical connection H_(LOAD1).

The controllable electrical outlet 200 may further comprise a secondload-side hot electrical connection H_(LOAD2) and a second load-sideneutral electrical connection N_(LOAD2), which may also be provided atan electrical receptacle (e.g., the lower switched receptacle 114 of thecontrollable electrical outlet 110) for powering a second electricalload (e.g., a second plug-in electrical load). The controllableelectrical outlet 200 may comprise a load control circuit 210 (e.g., acontrollable switching circuit, such as a relay) coupled in serieselectrical connection between the line-side hot electrical connectionH_(LINE) and the second load-side hot electrical connection H_(LOAD2).The load control circuit 210 may comprise a relay having a single-polesingle-throw (SPST) mechanical switch coupled in series electricalconnection between the line-side hot electrical connection H_(LINE) andthe second load-side hot electrical connection H_(LOAD2) and at leastone operating coil for opening and closing the SPST switch. The loadcontrol circuit 210 may be rendered conductive and non-conductive inresponse to a control circuit 212 (e.g., a digital control circuit) toprovide a switched-hot voltage (e.g., the switched-hot voltage V_(SH))at the second load-side hot electrical connection H_(LOAD2) for turningthe second electrical load on and off. For example, the control circuit212 may be coupled to the at least one operating coil of the relay foropening and closing the SPST switch of the relay. The control circuit212 may include one or more of a processor (e.g., a microprocessor), amicrocontroller, a programmable logic device (PLD), a field programmablegate array (FPGA), an application specific integrated circuit (ASIC), orany suitable processing device.

The controllable electrical outlet 200 may further comprises a thirdload-side hot electrical connection H_(LOAD3) and a third load-sideneutral electrical connection N_(LOAD3). For example, the thirdload-side hot electrical connection H_(LOAD3) may be provided at a wiredelectrical connection, such as a screw terminal (e.g., the controlledwired output 116 of the controllable electrical outlet 110) for poweringone or more downstream standard electrical outlets (e.g., the standardelectrical outlets 120). The third load-side neutral electricalconnection N_(LOAD3) may also be provided at a screw terminal. However,the third load-side neutral electrical connection N_(LOAD3) may be anoptional connection since the third load-side neutral electricalconnection N_(LOAD3) is coupled to the line-side neutral electricalconnection N_(LINE) (e.g., which is coupled to the neutral side of theAC power source 202). The switched-hot voltage V_(SH) may be provided atthe third load-side switched-hot electrical connection H_(LOAD3). Thedownstream electrical outlets may receive the switched-hot voltageV_(SH) via an electrical wire 208 (e.g., the electrical wire 128 of FIG.1). The control circuit 212 may be configured to control the loadcontrol circuit 210 for connecting power to or disconnecting power fromone or more of the receptacles of each of the downstream electricaloutlets. The downstream electrical outlets may receive the hot voltageV_(H) via an electrical wire (e.g., the electrical wire 126 of FIG. 1)that is wired to the line-side hot electrical connection H_(LINE) in theelectrical wallbox of the controllable electrical outlet 200.

Alternatively or additionally, the load control circuit 210 may comprisea dimmer circuit or driver circuit for controlling the amount of powerdelivered to the electrical loads connected to the second load-side hotelectrical connection H_(LOAD2), the third load-side hot electricalconnection H_(LOAD3), and/or the downstream electrical outlets. Forexample, the load control circuit 210 may comprise a bidirectionalsemiconductor switch (e.g., a triac), which may be controlled by thecontrol circuit 212 using a standard phase-control dimming technique.

The controllable electrical outlet 200 may comprise one or more sensecircuits for detecting and/or measuring the power being consumed by theelectrical loads plugged into the controllable electrical outlet 200and/or the downstream electrical outlets. For example, the controllableelectrical outlet 200 may comprise a first sense circuit 214 coupled inseries between the line-side hot electrical connection H_(LINE) and thefirst load-side hot electrical connection H_(LOAD1) for measuring a loadcurrent conducted by the first electrical load, and a second sensecircuit 216 coupled in series with the load control circuit 210 formeasuring a load current conducted by the second electrical loads andone or more electrical loads plugged into the downstream electricaloutlets. The sense circuits 214, 216 may generate respective first andsecond sense signals V_(S1), V_(S2) that are received by the controlcircuit 212 and are representative of the magnitudes of the respectiveload currents.

While the downstream electrical outlets may receive the hot voltageV_(H) via an electrical wire that is wired to the line-side hotelectrical connection H_(LINE) as described above, the downstreamelectrical outlets could (e.g., alternatively) receive power through thecontrollable electrical outlet 200. For example, the controllableelectrical outlet 200 could comprise one or more additional electricalconnections to which the unswitched receptacles of the downstreamelectrical outlets could be connected. The first sense circuit 214 couldbe coupled to the additional electrical connections, for example, suchthat a total load current of the first electrical load and theunswitched receptacles of the downstream electrical outlets may beconducted through the first sense circuit 214. Accordingly, themagnitude of the first sense signal V_(S1) generated by the first sensecircuit 214 may be representative of the total load current of theunswitched electrical loads coupled to the controllable electricaloutlet 200, and the magnitude of the second sense signal V_(S2)generated by the sense circuit 216 may be representative of the totalload current of the switched electrical loads controlled by thecontrollable electrical outlet 200.

The controllable electrical outlet 200 may comprise a communicationcircuit 218, for example, a wireless communication circuit (e.g., an RFtransceiver) coupled to an antenna 220 for transmitting and receivingdigital messages (e.g., via wireless signals, such as the RF signals 108of FIG. 1) at a specified frequency (e.g., a transmission frequency,such as 434 MHz or 2.4 GHz). The communication circuit 218 may beconfigured to receive the digital messages via the RF signals 108according to a predefined RF communication protocol, such as, forexample, one or more of LUTRON CLEAR CONNECT, WIFI, BLUETOOTH, ZIGBEE,Z-WAVE, KNX-RF, LTE, or ENOCEAN RADIO protocols. Alternatively, thecommunication circuit 218 may comprise an RF transmitter fortransmitting RF signals and/or an RF receiver for receiving RF signals.The antenna 220 may comprise a resonant loop antenna as will bedescribed in greater detail below.

The controllable electrical outlet 200 may comprise a memory 222communicatively coupled to the control circuit 212. The control circuit212 may be configured to use the memory 222 for the storage and/orretrieval of, for example, the serial numbers of the input devices(e.g., the wireless transmitters) to which the controllable electricaloutlet 200 is responsive (e.g., to which the controllable electricaloutlet is associated). The memory 222 may be implemented as an externalintegrated circuit (IC) or as an internal circuit of the control circuit212.

The controllable electrical outlet 200 may comprise one or moreactuators 224 (e.g., buttons) for providing manual user inputs to thecontrol circuit 212. For example, the control circuit 212 may beconfigured to control the load control circuit 210 to render the relayconductive and non-conductive in response to actuations of the actuators224. In addition, the control circuit 212 may be configured to associatethe controllable electrical outlet 200 with one or more of the inputdevices (e.g., the remote control device 130, the occupancy sensor 140,and the controller 150) in response to actuations of one or more of theactuators 224 (e.g., the programming button 118 of the controllableelectrical outlet 110). The controllable electrical outlet 200 may alsocomprise a visual indicator circuit 226 that may comprise one or moreLEDs for illuminating at least one visual indicator (e.g., the visualindicator 119) for providing feedback to a user during configurationand/or normal operation.

The controllable electrical outlet 200 may include a power supply 228coupled between the line-side hot electrical connection H_(LINE) and theline-side neutral electrical connection N_(LINE) for generating a DCsupply voltage V_(CC) for powering one or more of the control circuit212, the communication circuit 218, the memory 222, and otherlow-voltage circuitry of the controllable electrical outlet 200. Forexample, the power supply 228 may comprise a non-isolated power supply(e.g., a Class 1 power supply) or an isolated power supply (e.g., aClass 2 power supply).

The control circuit 212 may be configured to control the load controlcircuit 210 to render the relay conductive and non-conductive inresponse to digital messages received via RF signals from input devices(e.g., the remote control device 130, the occupancy sensor 140, and thesystem controller 150 shown in FIG. 1). For example, the control circuit212 may receive digital messages including commands for providing manualcontrol of the switched electrical loads (e.g., from the remote controldevice 130) and/or for providing automated control of the switchedelectrical loads (e.g., from the occupancy sensor 140 and/or the systemcontroller 150). A system controller (e.g., the system controller 150)may be configured to transmit digital messages to the controllableelectrical outlet 200 to control the switched electrical loads inaccordance with one or more timeclock events of a timeclock schedule,for example, to turn on the switched electrical loads during the day andto turn off the switched electrical loads at night. In addition, thecontrol circuit 212 may be configured to cause the communication circuit218 to transmit, for example, one or more digital messages includinginformation regarding the power consumed by the unswitched and/orswitched electrical loads to the system controller.

After controlling the load control circuit 210 in response to digitalmessages received via the communication circuit 218, the control circuit212 may be configured to store in the memory 222 information regardingthe type of input device from which the communication circuit 218received the digital message, and/or how the control circuit 212controlled the load control circuit 210 in response to that digitalmessage. The control circuit 212 may transmit this information to thesystem controller for analysis regarding how much energy is saved inresponse to certain types of input devices. For example, the systemcontroller 150 may be configured to determine how much energy is savedas a result of the controllable electrical outlet 200 turning off thecontrolled electrical loads in response to the occupancy sensor 140versus how much energy is saved as a result of the controllableelectrical outlet turning off the controlled electrical loads inresponse to the remote control device 130.

The control circuit 210 may be configured to measure the amount of powerconsumed by the unswitched electrical loads (e.g., in response to thefirst sense signal V_(S1) generated by the first sense circuit 214)and/or to determine the amount of power consumed by the switchedelectrical loads (e.g., in response to the second sense signal V_(S2)generated by the sense circuit 216). The control circuit 210 may beconfigured to determine a balance between the amount of power consumedby the unswitched and switched electrical loads and report thisinformation to the system controller. The controllable electrical outlet200 and/or the system controller may be configured to transmit a digitalmessage including an alert that the amount of power consumed by theunswitched and switched electrical loads is unbalanced (e.g., in anemail or text message).

FIG. 3 is a perspective view and FIG. 4 is a front view of an examplecontrollable electrical outlet 300, which may be an example of thecontrollable electrical outlet 110 of FIG. 1 and/or the controllableelectrical outlet 200 of FIG. 2. The controllable electrical outlet 300may be mounted to a standard electrical wallbox. The controllableelectrical outlet 300 may comprise a bezel portion 310 having a frontsurface 311 adapted to be received through an opening of a faceplate312. The controllable electrical outlet 300 may include circuitry thatis similar to the circuitry of the controllable electrical outlet 200.The circuitry may be housed in a rear enclosure portion 314 of thecontrollable electrical outlet 300, for example, such that a wirelesscommunication circuit (e.g., the wireless communication circuit 218) maybe located inside of the wallbox. An actuator, such as a programmingbutton 318 (e.g., one of the actuators 224) may be provided on the bezelportion 310. The programming button 318 may be actuated to associate thecontrollable electrical outlet 300 with one or more input devices (e.g.,wireless transmitters). The controllable electrical outlet 300 may alsocomprise a visual indicator 319 that may be illuminated to providefeedback to a user during configuration and/or normal operation. Forexample, the visual indicator 319 may be illuminated by a light source(e.g., an LED of the visual indicator circuit 226) located inside of thecontrollable electrical outlet 300.

The front surface 311 of the bezel 310 may be located in a planeextending in a longitudinal direction L and a lateral direction A asshown in FIG. 4. The bezel portion 310 may comprise an upper receptacle320 and a lower receptacle 322 for receiving the plugs of plug-inelectrical loads. The upper receptacle 320 and the lower receptacle 322may be spaced apart from each other in the longitudinal direction L. Forexample, the upper receptacle 320 may be an unswitched receptacle (e.g.,similar to the upper receptacle 112 of the controllable electricaloutlet 110 and/or the first load-side hot and neutral electricalconnections H_(LOAD1), N_(LOAD1) of the controllable electrical outlet200) and the lower receptacle 322 may be a switched receptacle (e.g.,similar to the lower receptacle 114 of the controllable electricaloutlet 110 and/or the second load-side hot and neutral electricalconnections H_(LOAD2), N_(LOAD2) of the controllable electrical outlet200). Each of the upper and lower receptacles 320, 330 may comprise arespective hot opening 322, 332 for receiving a hot blade of a plug, arespective neutral opening 324, 334 for receiving a neutral blade of theplug, and a respective ground opening 326, 336 for receiving a groundblade of the plug.

The rear enclosure portion 314 may comprise a hot screw terminal 318 forreceiving a hot voltage from an AC power source (e.g., the line voltageinput 115 of the controllable electrical outlet 110 and/or the line-sidehot electrical connection H_(LINE) of the controllable electrical outlet200). The rear enclosure portion 314 may also comprise at least oneneutral terminal (not shown) adapted to be coupled to the neutral sideof the AC power source (e.g., the line-side neutral electricalconnection N_(LINE) of the controllable electrical outlet 200). The rearenclosure portion 314 may also comprise a wired-output screw terminal319 adapted to be electrically connected to one or more downstreamstandard electrical outlets. The controllable electrical outlet 300 mayprovide a switched-hot voltage V_(SH) at the wired-output screw terminal319, such that the controllable electrical outlet 300 may be able toconnect power to or disconnect power from one or more of the receptaclesof one or more downstream electrical outlets. Examples of controllablereceptacles are described in greater detail in commonly-assigned U.S.Patent Application Publication No. 2015/0249337, published Sep. 3, 2015,entitled CONTROLLABLE ELECTRICAL OUTLET WITH A CONTROLLED WIRED OUTPUT,the entire disclosure of which is hereby incorporated by reference.

While the controllable electrical outlet 300 shown in FIGS. 3 and 4 hasU.S. style receptacles, the controllable electrical outlet 300 mayalternatively or additionally have receptacles of styles used in othercountries. In addition, the controllable electrical outlet 300 couldcomprise other types of receptacles, for example, one or more UniversalSerial Bus (USB) connectors, and an internal power supply for chargingan electrical device, such as the battery of a smart phone.

FIG. 5 is a front view and FIG. 6 is a left side view of a portion ofthe controllable electrical outlet 300 showing a main PCB 340, which mayhave mounted thereon the electrical circuitry of the controllableelectrical outlet (e.g., as shown in FIG. 2). The main PCB 340 may belocated in a plane extending in the longitudinal direction L and thelateral direction A as shown in FIG. 5 (e.g., parallel to the plane ofthe front surface 311 of the bezel portion 310). The controllableelectrical outlet 300 may include a pair of upper hot contacts 350 and apair of upper neutral contacts 352 configured to mechanically connect to(e.g., pinch) the hot and neutral blades of a plug, respectively, thatare received through the upper hot and neutral openings 322, 324 inorder to provide electrical connection to the hot and neutral blades.The controllable electrical outlet 300 may also include a pair of upperground contacts 354 configured to mechanically connect to (e.g., pinch)the ground blade of the plug, which may be received through the upperground opening 326. The controllable electrical outlet 300 may include apair of lower hot contacts 360 and a pair of lower neutral contacts 362configured to mechanically connect to (e.g., pinch) the hot and neutralblades of a plug, respectively, that are received through the lower hotand neutral openings 332, 334 in order to provide electrical connectionto the hot and neutral blades. The controllable electrical outlet 300may also include a pair of lower ground contacts 364 configured tomechanically connect to (e.g., pinch) the ground blade of the plug,which may be received through the lower ground opening 336.

The controllable electrical outlet 300 may include a load controlcircuit (not shown) for controlling the power delivered to the plug-inelectrical loads plugged into the upper and lower receptacles 320, 330.The load control circuit may be mounted to the main PCB 340. Forexample, the upper and lower receptacles 320, 330 may be controlled inunison because the upper contacts 350, 352 are coupled to the lowercontacts 360, 362 by respective electrical contact coupling members,e.g., hot and neutral coupling members 370, 372 that extend in thelongitudinal direction L between the contacts. The hot and neutralcoupling members 370, 372 may be cut (e.g., made non-conductive at apoint along the length) to provide for separate control of the upper andlower receptacles 320, 330. The upper ground contacts 354 may be coupledto the lower ground contacts 364 by a ground coupling member 374, whichmay be coupled to mounting tabs 376 of the controllable electricaloutlet 300. The ground coupling member 374 may extend in thelongitudinal direction L between the mounting tabs 376.

If the load control circuit of the controllable electrical outlet 300 isconfigured to adjust the amount of power delivered to the plug-inelectrical loads (e.g., the load control circuit is a dimmer circuit),the respective electrical outlet may comprise a protrusion at thecontrolled receptacle for preventing a standard electrical plug frombeing plugged into the controlled receptacle. Examples of suchprotrusions for preventing standard plugs from being plugged into acontrolled receptacle are described in greater detail incommonly-assigned U.S. Pat. No. 7,198,523, issued Apr. 3, 2007, and U.S.Pat. No. 7,311,558, issued Dec. 25, 2007, both entitled RECEPTACLE ANDPLUG THEREFOR, the entire disclosures of which are hereby incorporatedby reference.

The controllable electrical outlet 300 may also comprise a resonant loopantenna 400 having an antenna PCB 402. FIGS. 7 and 8 show first andsecond layers 410, 412, respectively, of the antenna PCB 402, where thefirst and second layers may be overlaid over each other. The antenna PCB402 may be made of a non-conductive substrate, and may be substantiallyrectangular or square in shape. The antenna PCB 402 may comprise firstand second tabs 404, 406 at a bottom edge 408 of the antenna PCB. Thefirst and second tabs 404, 406 may be received in openings in the mainPCB 340, such that the antenna PCB 402 may be mechanically connected tothe main PCB and oriented perpendicular to a plane of the main PCB.

The resonant loop antenna 400 may comprise a main loop trace 412 (e.g.,a main loop) disposed on (e.g., laid out on) the first layer 410, whichmay be an outer layer of the antenna PCB 402. The main loop trace 412may be located near a top side 405 of the antenna PCB 402. The main looptrace 412 may have a break 414 with a capacitor 416 provided across thebreak. The capacitor 416 may be a variable capacitor to allow for tuningof a resonant frequency of the main loop trace 412. The first layer 410may also have first and second electrical pads 418, 419 on the first tab404 to allow for electrical connection to communication circuit 218(e.g., the RF transceiver) on the main PCB 340 (e.g., soldered toelectrical pads on the main PCB). The second tab 406 may providemechanical support for the antenna PCB 402.

The resonant loop antenna 400 may also comprise a feed loop trace 422(e.g., a feed loop) disposed on (e.g., laid out on) the second layer420, which may be another outer layer or an internal layer of theantenna PCB 402. The feed loop trace 422 may be coupled to electricalpads 418, 419 on the first layer 410 through vias 424. The firstelectrical pad 418 may be electrically coupled to the RF transceiver onthe main PCB (e.g., the RF feed) and the second electrical pad 419 maybe electrically coupled to an antenna ground. The main loop trace 412 onthe first layer 410 may overlap the feed loop trace 422 on the secondlayer 420. The feed loop trace 422 does not extend to the top edge 405of the antenna PCB 402 as shown in FIG. 8. The main loop trace 412 maybe magnetically coupled to the feed loop trace 422 and may beelectrically isolated from the feed loop trace. When a signal istransmitted from the RF transceiver to the first electrical pad 418,current may flow through the feed loop trace 422 on the second layer420. This may cause current to be induced in the main loop trace 412 onthe first layer 410 due to the magnetic coupling of the main loop trace412 and the feed loop trace 422 resulting in an RF signal beingtransmitted from the controllable electrical outlet.

FIG. 9 shows an example equivalent circuit of the resonant loop antenna400. The main loop (e.g., the main loop trace 420) may be the primaryradiating element of the antenna 400 and may include an inductance L andcapacitance C in series (e.g., where the capacitance C may be a variablecapacitance). When energized, the main loop may resonate at a frequencydetermined by the values of the inductance L and the capacitor C andenables the transmitting and receiving of RF signals via a radiationresistance R_(r), which may be a representation of the energy deliveredto radiation. The losses in the main loop may be represented by a lossresistance R_(l). The main loop may be primarily magnetically coupled tothe feed loop (e.g., the feed loop trace 422). This coupling is shownschematically in FIG. 9 by an ideal transformer T. The feed loop mayinclude a magnetizing inductance L_(m), a leakage inductance L_(l), andtwo ends 430 that connect to the RF transceiver. The feed loop may allowfor the conduction of signals between the RF transceiver and the mainloop.

In this way, the antenna 400 may be adapted to receive RF signals viathe main loop, with those radio frequency signals beingelectromagnetically coupled to the feed loop for input to the RFtransceiver. Conversely, the feed loop may receive a feed signal to betransmitted from the RF transceiver, and may electromagnetically couplesthe feed signal to the main loop for transmission of RF signals to anexternal wireless device (e.g., the system controller 150). Examples ofload control devices having resonant loop antennas are described ingreater detail in commonly-assigned U.S. Pat. No. 7,362,285, issued Apr.22, 2008, entitled COMPACT RADIO FREQUENCY TRANSMITTING AND RECEIVINGANTENNA AND CONTROL DEVICE EMPLOYING SAME, and U.S. Pat. No. 7,592,967,issued Sep. 22, 2009, entitled COMPACT ANTENNA FOR A LOAD CONTROLDEVICE, the entire disclosures of which are hereby incorporated byreference.

Referring back to FIGS. 5 and 6, the antenna PCB 400 may be orientedperpendicular to the plane of the main PCB 340 and may extend from themain PCB 340 towards the front surface 311 in a transverse direction T.The antenna PCB 400 may be arranged substantially parallel to the groundcoupling member 374, e.g., in a plane extending in the longitudinaldirection L and the transverse direction T as shown in FIG. 6. As shownin FIG. 5, the antenna PCB 400 may be centrally located in thecontrollable electrical outlet 300 and may be located away (e.g., as faraway as possible) from the contacts 350-364 and the coupling members370-374. The antenna PCB 400 may be located away from the upper contacts350, 352 and the lower contacts 360, 362 in the longitudinal direction L(e.g., approximately centrally located between the upper contacts andthe lower contacts). As shown in FIG. 5, the antenna PCB 400 may belocated away from the neutral coupling member 372 and the groundcoupling member 374 in the lateral direction A (e.g., approximatelycentrally located between the neutral coupling member 372 and the groundcoupling member 374). Alternatively, the antenna PCB 400 may be locatedbetween (e.g., approximately centrally located between) the hot couplingmembers 370 and the ground coupling member 374. In addition, the antennaPCB 400 may also be arranged in a plane extending in the lateraldirection A and the transverse direction T, for example, if the groundcoupling member 374 does not extend adjacent to the center of the mainPCB 340, but extends near the edges of the main PCB. While not shown inFIGS. 5 and 6, the contacts 350-364 and the coupling members 370-374 maybe supported by a cradle (e.g., a plastic, non-conductive supportcradle), which may be positioned between the main PCB 340 and thecontacts and coupling members. The cradle (not shown) may include anopening through which the antenna PCB 400 may extend.

As shown in FIG. 6, the main loop trace 412 may be mostly located abovethe hot and neutral coupling members 370, 372 in a direction extendingfrom the main PCB 340 towards the front surface 311 of the controllableelectrical outlet 300 (e.g., along the transverse direction T, i.e., tothe right in FIG. 6), which may improve the RF performance of thecontrollable electrical outlet 300. A top edge 442 of a lower portion440 of the main loop trace 412 may be positioned above the hot andneutral coupling members 370, 372 in the transverse direction T, suchthat an inner portion 444 of the main loop trace 412 may not overlapwith the coupling members 370, 372 in the transverse direction T (e.g.,when viewed from the side as shown in FIG. 6).

The RF performance of the controllable electrical outlet 300 may besubstantially immune to devices plugged into the receptacles 320, 322(e.g., plugs, power supplies, control devices, etc.) due to the magneticcoupling between the main loop trace 412 and the feed loop trace 422 andthe orientation of the main loop trace (e.g., perpendicular to the planeof the main PCB 340). For example, degradation of the RF performance ofthe controllable electrical outlet 300 may be less when the controllableelectrical outlet includes the resonant loop antenna 400 rather thanother types of antennas, such as a monopole antenna.

Since the main loop trace 412 may be electrically isolated from the feedloop trace 422 and the AC power source to which the controllableelectrical outlet 300 is coupled (e.g., the AC power source 102, 202),the top edge 405 of the antenna PCB 402 may be located close to thefront surface 311 and the receptacles 320, 322 of the controllableelectrical outlet. In addition, because the main loop trace 412 may beisolated from the feed loop trace 422, the controllable electricaloutlet 300 does not need to include an isolated power supply forpowering the communication circuit 218, but can include a non-isolatedpower supply, which may be lower cost and smaller than an isolated powersupply.

What is claimed is:
 1. A controllable electrical outlet including: a hotvoltage input terminal; an unswitched hot voltage output terminalconductively coupled to the hot voltage input terminal; an unswitchedelectrical receptacle conductively coupled to the hot voltage inputterminal; a switched electrical receptacle; a switching circuitconductively between the hot voltage input terminal and the switchedelectrical receptacle, the switching circuit including: memory circuitryto store data representative of a remote input device; communicationcircuitry to receive an RF signal from the remote input device via aresonant loop antenna, the resonant loop antenna comprising a feed loopelectrically coupled to the communication circuit and a main loopmagnetically coupled to the feed loop; and control circuitry operativelycoupled to the memory circuit and the communication circuitry, thecontrol circuitry to: cause a transition the switching circuitry betweena conductive state and a non-conductive state responsive to receipt of atransition signal from the remote input device; and a switched hotvoltage output terminal conductively coupled to the switching circuit.2. The controllable electrical outlet of claim 1, further comprising: aload control circuit to control power delivered to the switched electricreceptacle; wherein the control circuitry to further: cause the loadcontrol circuit to adjust power delivered to the switched electricreceptacle responsive to receipt, via the resonant loop antenna, of apower adjustment signal from the remote input device.
 3. Thecontrollable electrical outlet of claim 1, wherein the resonant loopantenna includes an antenna printed circuit board, the main loopincluding a main loop trace disposed on a first layer of an antennaprinted circuit board, the main loop having an inductance and acapacitance that are resonant at a specified frequency, and the feedloop including a feed loop trace disposed on a second layer of theantenna printed circuit board and electrically coupled to thecommunication circuitry.
 4. The controllable electrical outlet of claim3, further comprising a main printed circuit board on which the loadcontrol circuit is mounted; wherein the antenna printed circuit board isarranged perpendicular to the main printed circuit board.
 5. Thecontrollable electrical outlet of claim 4, further comprising: a bezelportion having a front surface located in a plane extending in alongitudinal direction and a lateral direction, the switched electricreceptacle and the unswitched electric receptacle disposed on the frontsurface of the bezel portion and spaced apart from each other in thelongitudinal direction; and wherein the main printed circuit board islocated in a plane parallel to the plane of the front surface of thebezel portion, and the antenna printed circuit board extends from themain printed circuit board in a transverse direction perpendicular tothe plane of the main printed circuit board.
 6. The controllableelectrical outlet of claim 5, wherein the switched electric receptaclecouples to the unswitched electric receptacle via an electrical contactcoupling member that extends in the longitudinal direction.
 7. Thecontrollable electrical outlet of claim 6, wherein a ground contact ofthe switched electric receptacle couples to a ground contact of theunswitched electric receptacle via a ground coupling member that extendsin the longitudinal direction.
 8. The controllable electrical outlet ofclaim 7, wherein the antenna printed circuit board of the controllableelectrical outlet is located between the electrical contact couplingmember and the ground coupling member, the antenna printed circuit boardspaced apart from the coupling members in the lateral direction andspaced apart from the switched and the unswitched electric receptaclesin the longitudinal direction.
 9. The controllable electrical outlet ofclaim 6, wherein the antenna printed circuit board of the controllableelectrical outlet is located in a plane extending in the longitudinaldirection and the transverse direction.
 10. The controllable electricaloutlet of claim 2, wherein the main loop of the resonant loop antenna ofthe controllable electrical outlet is electrically isolated from thefeed loop.
 11. The controllable electrical outlet of claim 10, whereinthe main loop trace of the resonant loop antenna is located near a topedge of the antenna printed circuit board and the feed loop trace doesnot extend to the top edge of the antenna printed circuit board.
 12. Thecontrollable electrical outlet of claim 1, wherein the remote inputdevice comprises a system controller, the system controller configuredto include a command included in the RF signal transmitted by the remoteinput device.
 13. The controllable electrical outlet of claim 12, thecontrol circuitry to further: transmit feedback information to thesystem controller.
 14. The controllable electrical outlet of claim 13,wherein the feedback information comprises at least one of: datarepresentative of a status of an electric load device conductivelycoupled to the switched electric receptacle or data representative of anenergy consumption of the electric load device conductively coupled tothe switched electric receptacle.
 15. The controllable electrical outletof claim 12, wherein the command includes at least one of a timeclockcommand, a load shed command, a demand response command, and a peakdemand command.
 16. The controllable electrical outlet of claim 1, thecontrol circuitry to further: compare data representative of a remoteinput device identifier included in one or more signals received via thecommunication circuitry with the data representative of the remotedevice identifier stored in the memory circuitry; and responsive to afavorable comparison of the data representative of the remote inputdevice identifier included in the one or more signals received via thecommunication circuitry with the data representative of the remotedevice identifier stored in the memory circuitry, execute one or moreinstructions included in the one or more signals.
 17. The controllableelectric outlet of claim 16, further comprising: a programming button;wherein the control circuitry to further, responsive to actuation of theprogramming button: store the data representative of the remote deviceidentifier in the memory circuitry; and form a logical associationbetween the remote input device and the controllable electrical outlet.